Device for continuous winding of webs

ABSTRACT

A device for continuous winding of webs on winding shafts onto winding rollers consisting of arms supporting the winding shaft, a pressure roller that can be engaged on the winding shaft or winding core, a knife separating the web during the roller change, and of a charging electrode supplying the web start with an electrostatic charge, which attaches the web start, newly formed by the web cut, on the winding shaft. In order to always maintain the correct equal distance to the web supplied with the charge, the same is tracked in such a manner that the distance of the charging electrode to the web remains constant regardless of the diameter of the winding shaft.

This is a nationalization of PCT/EP02/07158 filed Jun. 28, 2002 andpublished in German.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a device for continuous winding of webs,preferably webs made of thermoplastic synthetic material, onto windingshafts or winding cores to winding rollers, with arms supporting thewinding shaft that is preferably equipped with a drive, with a pressureroller that can be engaged on the winding shaft or winding core, with aknife separating the web during a roller change, and with a device forstart winding of the new web start onto the winding shaft or windingcore that is formed by the web cut.

2. Description of the Related Art

A particular problem in devices of this type is start-winding the newweb start formed by the web cut during the roller change onto a newwinding shaft or winding core. It is known to apply an adhesive coatingonto the winding shaft or winding core, to which the web start adhereson the winding shaft or winding core, accelerated to web speed, forstart winding the web start of the web fed at a constant speed. However,manageability of winding shafts or winding cores equipped with adhesivecoatings is extensive and complicated. Furthermore, placining web startsaround the winding core or winding shaft by means of ring-shaped vacuumchannels, or special ring-shaped guide channels with insert wedges,until the second enlacement attaches the web start onto the winding coreis known. Such devices are also relatively complicated and extensive.

SUMMARY OF THE INVENTION

The aim of the invention to create a device of the previously statedtype, which independent from the respective diameter of the windingshaft or of the winding core enable simple winding of web starts formedby web cuts during the roller change onto winding shafts or windingcores.

This task is solved according to the present invention by a device forcontinuous winding of webs, preferably webs made of thermoplasticsynthetic material, onto winding shafts or winding cores to windingrollers. The device includes a pressure roller that can be engaged onthe winding shaft or winding core, with a knife separating the webduring a roller change, and with a device to start winding of a new webstart, as formed by the web cut, onto the winding shaft or winding core.The start winding device includes a charging electrode that is equippedwith at least one electrostatic charge and, with the knife, is arrangedin machine direction of the web behind the winding shaft or windingcore. The start winding device is connected to the pressure roller whichis movable by means of a gear in such a manner that the distance betweenthe charging electrode and the web remains substantially constantregardless of the diameter of the winding shaft or winding core.

According to a preferred embodiment it is provided that the device, forwinding consists of a charging electrode equipped with an electrostaticcharge located at the web start, which is arranged at a predetermineddistance to the web and coupled to the traveling pressure coil via ofgear means, in such a manner that their distance to the web remainsconstant regardless of the diameter of the winding shaft or windingcore.

It is known from U.S. Pat. No. 4,852,820 to get the web start formed bya web cut of a continuously fed film web in adhesive contact with awinding coil or winding core in such a manner that the web start isequipped with an electrode with an electrostatic charge, which actuatesthis adhesion. However, the necessary electrostatic charge can only beapplied to the web start formed by the web cut in an optimum mannerbefore the web cut is performed, if the charging electrode has thecorrect predetermined distance to the web. Webs and preferably film websof different diameters are usually wound onto winding rollers or windingcores of winding devices so that maintaining the correct predetermineddistance of the charging electrode to the web can present a problem. Inthe device according to the invention, the charging electrode alwaysadjusts to the correct predetermined distance to the web, in that it istracked by means of tracking devices in such a manner that the distanceto the web remains constant regardless of the diameter of the windingshaft or winding core.

A preferred embodiment provides that the pressure roller is supported ina carriage traveling in a frame, and the charging electrode expandingacross the width of the web is held between the arms of two-armedlevers, which are pivot-supported on lateral components or the carriage,and that the other arms of the two-armed levers carry link blocks orrollers that are designed according to the required tracking movement ofthe charging electrode.

Purposefully, the carriage can travel on or parallel to a surface, whichis spanned by means of the axes of the winding shaft and of the pressureroller.

The carriage can travel in the frame by means of a gear motor, thepinion gear of which combs with a gear rod of the carriage. Controllingthe gear motor can be achieved by means of a computer.

Purposefully, the knife is held at the carrier that carries the chargingelectrode. According to a simple embodiment it is provided that theknife is moveable from a pneumatic cylinder without a piston rod at aright angle to the web.

In order to enable winding from left to right, a second trackingcharging electrode with a knife is arranged laterally reversed from theplane, which is spanned by means of the axes of the winding shaft andthe pressure roller in a preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment example of the invention is explained in further detailbelow based on the drawing. It shows:

FIG. 1 a side view of the winding device according to the invention witha distant front side wall of the frame,

FIG. 2 the device drawn from FIG. 1 for adjusting a constant distance ofthe charging electrode, which is independent of the diameter of thewinding shaft, to the newly to be wound web start at the time of cuttingthe web during a roller change,

FIGS. 3–6 the different positions of the charging electrode to thewinding cores of different diameters according to FIG. 2, and

FIG. 7 a top view of the device according to FIGS. 2 to 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

FIG. 1 shows a rear plate-shaped side component 1, which is part of aframe. The front side component is removed in order to better view thedevices arranged between the side components.

A carriage is guided horizontally movable between the side components 1.Only the side wall 2 is illustrated of the carriage, as the front sidewall is again removed for reasons of better illustration. The side walls2 of the carriage are connected to each other by traverse members notillustrated. The side walls 2 are guided in a movable manner in guides 3of the side components 1 that are illustrated in broken lines. At itsupper side edge, the side wall 2 at the minimum is equipped with a gearrod 4 having teeth that mesh with the pinion gear 5 of a gear motor 6,which is controlled by the electronic machine control for moving thecarriage with the side walls 2.

On both sides of a shaft 7 that is supported between the side walls 2,two-armed levers 8 are pivot-supported, the arms 10 of which point inthe direction of the winding core 9, which carry the charging electrode12 that expands across the width of the web 11. The interior arms 13 ofthe two-armed lever 8 are equipped with axle journals 14, on whichrollers 15 are supported, which are guided in guides 16 of the sidecomponents 1 of the frame, and which consist of slotted holes. Theguides 16 consist of a laterally extending section 17 and connected tothe same, of a section 18 extending parallel to the guide 3.

Not only is the electrode 12 attached to the arms 10 of the two-armedlever 8 extending toward the exterior, but additionally also a linearunit, such as a piston rod-less pneumatic cylinder, which moves a knife19 across the width of the web 11 for the purpose of cutting the web 11.

On both sides of the shaft 7 rockers 20 are pivot-supported on theinterior sides of the carriage side walls 2, which are pivoted by meansof the pneumatic cylinder 23, the piston rods 21 of which arepivot-supported on journals 22 of the rockers 20. The cylinders 23 arepivot-supported on journals 24 of the carriage side walls 2.

Tension springs 25 are arranged below the pneumatic cylinders 23parallel to the same, the ends of which are suspended from journals 26of the rocker 20, and journals 27 of the side wall 2.

The rockers 20 carry axle journals 30 above the pneumatic cylinders 23,on which coupling elements 31 are supported. At their rear ends, thecoupling elements 31 are pivot-connected to guides 32 in the jointpoints 33, the upper ends of which are pivot-supported on axle journals34 of the side walls 2. The coupling elements 31 transfer the rockers 20in the direction of the winding core 9. The pressure roller 38 issupported between the free ends of the piston rods 31.

The electrode 12 may consist of a number of needles, and is laterallyencased by rails, which provide protective cover.

The arrangement of the knife 19 with the cylinder on the carrier of theelectrodes 12 results in a cut closely above the roller gap between thewinding core 9 and the pressure roller 38 once the knife is activated sothat a web start with a short flap is created.

The web 11 moves in the direction of arrow A, and is fed to the pressureroller 38 by a guide roller 39, which may be supported, for example,between the-side walls 2 of the carriage.

The two-armed levers 8 with electrodes 12 and knives 19, as well as theguides 16 for the rollers 15 of the interior arms of the two-armedlevers 8, are arranged laterally reversed to a midplane 40, whichextends through the axes of the winding core 9 and the pressure roller38. In this way, a simple conversion of the winding device to wind fromleft to right is possible.

In order to further explain the invention, it is again described basedon FIGS. 4 to 7, which show the individual components and assemblygroups drawn from FIG. 1.

As FIG. 2 shows, the winding cores or winding shafts 9, 9′, 9″, 9′″ ofdifferent diameters can be inserted into the winding device. At eachwinding core or winding shaft, the same is pressed against therespectively inserted winding core by the movement of the carriage 2,and pressing on the pressure roller 38 by means of the pneumaticcylinder 23. By means of a respective movement of the carriage 2 in thedirection of arrow B, the two-armed lever 8 is pivoted by means of acorresponding movement of the rollers 15 in the inclined slotted holes16 in such a way that the electrodes 12 always have the same distance tothe web 11 winding off of the winding cores regardless of the diameterof the winding cores 9, 9′, 9″, 9′″.

As FIG. 2 shows, the web 11 runs across a guide roller 41 to the windingroller 42, which is almost completely wound between the other arms ofthe turret winder.

FIGS. 3 to 6 show the individual winding shafts or winding cores 9, 9′,9″, 9′″, on which the pressure roller 38 is engaged. Due to thecharacteristics of the incline of the guideway 16 and the design of thetwo-armed lever 8 it is ensured that the electrode 12 always adjustsitself to the correct distance A to the web 11 winding off of thewinding shaft or winding core by means of the corresponding movement ofthe carriage 2.

FIG. 7 shows a top view of components of the winding device, partiallyin a section. The side wall 1 of the frame is equipped with a slottedhole 16 forming a guide, in which the bottom roller 15 is guided, whichis supported on the lever arm 13 of the two,-armed lever 8 that isdirected toward the interior. The two-armed lever 8 is supported by anaxle journal 7 at the side wall 2 of the carriage, which is guidedacross guide pieces 44 in the direction of the double arrow C on guides3 of the frame. The arm 10 of the two-armed lever 8 pointing in thedirection of the winding core 9 carries the electrode 12, which suppliesan electrostatic charge to the web 11 winding off of the winding core 9during the roller change before the web cut is performed. This chargeoccurs in the known manner, whereby the winding shaft may have thecounter potential as opposed to the charging electrode 12.

The invention being thus described, it will be apparent that the samemay be varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be recognized by one skilled in the art areintended to be included within the scope of the following claims.

1. A device for continuous winding of webs onto winding shafts orwinding cores to winding rollers, comprising: a winding shaft or awinding core; a pressure roller that can be engaged on the winding shaftor winding core, said pressure roller being movable by a drivemechanism; a cutting element for severing the web during a windingroller change to form a new web start portion; and a start windingdevice to start winding of the new web start portion onto the windingshaft or winding core, said start winding device including a chargingelectrode that is equipped with at least one electrostatic charge; saidcutting element and said start winding device being arranged, in atraveling direction of the web, behind a point at which the pressureroller touches the winding shaft or winding core when engaged therewith;said start winding device being connected to said pressure roller sothat said start winding device moves when said pressure roller is movedby said drive mechanism, with a distance between the charging electrodeand the web thus being related to the movement of said pressure rollersuch that said distance remains substantially constant regardless of adiameter of the winding shaft or winding core; and said pressure rollerbeing supported in a carriage that is movable within a frame, saidcharging electrode being held between first arms of two-armed leverswhich are pivotally arranged on side walls of the carriage, second armsof said two-armed levers carrying link components which run along guideson the frame which are designed according to required movements of thecharging electrode to maintain said distance.
 2. The device according toclaim 1, wherein the carriage is moveable in or parallel to a planewhich is spanned by axes of the winding shaft or winding core and of thepressure roller.
 3. The device according to claim 2, further comprisinga second tracking charging electrode with a cutting element arrangedlaterally reversed from the plane which is spanned by axes of thewinding shaft or winding core and of the pressure roller.
 4. The deviceaccording to claim 1, wherein said link components are rollers.
 5. Thedevice according to claim 1, wherein said pressure roller is supportedin a carriage movable within a frame, said drive mechanism including amotor mounted to the frame and having a pinion gear that meshes withteeth on a gear rod of said carriage.
 6. The device according to claim1, wherein the carriage is moveable in the frame by means of a gearmotor having a pinion gear that meshes with teeth on a gear rod of thecarriage.
 7. The device according to claim 1, wherein the cuttingelement is held at a carrier that carries the charging electrode.
 8. Thedevice according to claim 1, wherein the cutting element is moveable ata right angle to the web by means of a pneumatic cylinder without apiston rod.
 9. A device for continuous winding of webs onto windingshafts or winding cores to winding rollers, comprising: a winding shaftor a winding core; a pressure roller that can be engaged on the windingshaft or winding core, said pressure roller supported in a carriage thatis movable between side components of a frame by a drive mechanism; acutting element for severing the web during a winding roller change toform a new web start portion; and a start winding device connected tosaid pressure roller for starting winding of the new web start portiononto the winding shaft or winding core, said start winding deviceincluding a charging electrode that is equipped with at least oneelectrostatic charge, said charging electrode spanning a width of saidweb and being held between first arms of two-armed levers which arepivotally arranged on side walls of said carriage, second arms of saidtwo-armed levers carrying linking components which run along guides ofsaid frame side components that are designed according to requiredtracking movements of the charging electrode such that movement of saidpressure roller by said drive mechanism causes said start winding deviceto move in said guides so that a distance between the charging electrodeand the web remains constant regardless of a diameter of the windingshaft or winding core.
 10. The device according to claim 9, wherein saidcutting element and said start winding device are arranged, in atraveling direction of the web, behind a point at which the pressureroller touches the winding shaft or winding core when engaged therewith.11. The device according to claim 9, wherein the drive mechanism formoving said carriage includes a gear motor having a pinion gear thatmeshes with teeth on a gear rod of the carriage.
 12. The deviceaccording to claim 11, wherein said linking components are rollers. 13.A device for continuous winding of webs onto winding shafts or windingcores to winding rollers, comprising: a winding shaft or a winding core;a pressure roller that can be engaged on the winding shaft or windingcore, said pressure roller being supported by a carriage movable betweenside components of a frame by a drive mechanism; a cutting element forsevering the web during a winding roller change to form a new web startportion; and a start winding device to start winding of the new webstart portion onto the winding shaft or winding core, said start windingdevice including a charging electrode that is equipped with at least oneelectrostatic charge; said start winding device being pivotallyconnected to said pressure roller carriage via a lever arm so as to bemovable with said pressure roller, said lever arm also being operativelycoupled with a guide in said frame having an angled portion relative tomovement of said carriage that changes a pivot angle of said startwinding device when said pressure roller carriage is moved relative tosaid frame and with said lever arm in said guide angled portion, saidguide adjusting said pivot angle to provide corresponding movement ofthe charging electrode such that a distance between the chargingelectrode and the web remains substantially constant regardless of adiameter of the winding shaft or winding core.
 14. The device accordingto claim 13, wherein said guide further includes a portion that extendsparallel with said carriage movement.
 15. The device according to claim13, wherein said guide includes slotted holes in said frame with saidlever arm having link blocks or rollers that run in said slotted holes.